This invention is generally directed toward a top for a land vehicle. More particularly, this invention is directed to a rigid cover for a pickup truck cargo bed. The present cover is composed of a first thermoformed sheet of plastic that provides a desirable application surface, and a second thermoformed sheet of plastic comprising molded-in details imparting strength, encapsulating hardware and other functional elements that advance the art of tops for land vehicles.
In the present embodiments, the first and second thermoformed sheets are permanently bonded together to produce a one-piece cover. Also included are one or more hinge elements operable to connect the cover to the truck bed about front wall; one or more props which support the cover in the opened position; and, a lock mechanism to secure the cover in the closed position.
Pickup truck vehicles are used for both work-related activities and personal transportation. The pickup truck bed provides carrying space for both work-related and personal cargo. In order to prevent cargo from being damaged by weather or stolen, it has become common to install a protective cover over the truck bed. There are four types of cover commonly available for this purpose. The most popular type of cover is referred to by industry as a xe2x80x9ctopperxe2x80x9d or a xe2x80x9ctruck capxe2x80x9d. A topper is characterized as having two opposed vertical side walls, a front wall and a back wall, which walls extend upward from the truck bed rails to form a roof with an over-all height generally equal to the top of passenger cabin of the pickup truck vehicle. The opposed sidewalls generally include windows for visibility, and the back wall includes a rear window lift gate for access. The three other types of covers for a truck bed are generically referred to as tonneau covers. The three types of tonneau cover comprise one-piece rigid covers; multi-piece sectional and roll-up covers; and, soft covers composed of a flexible vinyl fabric supported by cross-bows and optionally, a perimeter fabricated metal frame. The present invention falls under the category of one-piece rigid covers.
There are several prior art devises that disclose one-piece rigid tonneau covers. These prior art devises in turn include fiberglass reinforced plastic (FRP) covers; composite thermoset plastic covers and fabricated metal and/or plastic panel covers. By a considerable margin, the most popular and widely sold one-piece rigid covers are the FRP cover variety.
FRP cover products are produced by conventional lay-up operations are uneconomical compared to the modern technology of thermoform manufacturing operations.
The lay-up operation is time-consuming and labor intensive. The lay-up process involves the application of parting agents, a gel coat surface and two or more lamination steps that often include inserts for reinforcement. Each step is labor intensive and requires cure times that are influenced by temperature, humidity and other technical and labor factors. A single FRP tonneau cover mold is capable of producing 3-5 parts in a 24-hour period. Current thermoforming art is capable of converting sheets of plastic into rigid one-piece twin-sheet covers at a rate of 12 plus parts per hour. Thermoforming is a significantly more productive processing technology.
The lay-up operation uses polyester resins and fiberglass. The application surface of the lay-up process comprises specialty gel-coat resins that normally cost double the price of the polyester resins. An FRP cover for a small size pickup truck bed weighs approximately 95 lbs. The weight of the center of an FRP cover is so heavy that it collapses in upon itself when unsupported. Therefore, contemporary FRP covers also included filled resins and/or load-bearing inserts comprising wooden or aluminum cross members, foam panels or paperboard honeycomb panels that become saturated with resin between two laminations of FRP. A twin-sheet thermoformed plastic cover, for the equivalent make and model of pickup truck bed weighs 60 lbs. The resin costs for thermoformable plastics range in price, with HDPE at the low end and ABS at the high end. The material cost factor between FRP and thermoformable resins is in the order of 2 to 1. Thermoforming is therefore a much more economical processing technology.
The lay-up operation produces styrene monomer vapors that produce worker safety and environmental problems. The lay-up operation also poses cleanup and storage problems. The lay-up operation is taxed by many states to dis-incentivise its use and to re-cover its impact costs upon society. The thermoforming process of converting HDPE or ABS plastic resins into finish products carries little, if any risk, to society. Unlike thermosetting FRP resins, HDPE and ABS are 100% recyclable. Thermoforming is therefore a safer and cleaner processing technology.
The FRP lay-up operation has retained its prevalent position within the market because the manufacturers of tonneau covers also manufacture FRP toppers. The larger topper market, in terms of manufacturers"" sales revenue, has therefore precluded the move toward more promising thermoforming technologies. In summary, the existing manufacturers operate within a competitive market and are therefore reluctant to switch to more modern operations and technologies.
In addition to being uneconomical and having negative worker safety and environmental impacts, FRP covers are also not user friendly. The heavy weight construction of a FRP cover poses several problems. The FRP cover can not be easily removed from the truck bed because it of its heavy weight. A heavy weight FRP cover also increases fuel consumption and the cost of operating the vehicle. The heavy weight of an FRP cover can also damage the pickup truck box. For example, the unforgiving structure of a heavy weight burden upon the front and sidewall rails of a pickup truck can result in sheet metal deformation and warping. Furthermore, the heavy weight of the cover acts to compress and abrade the gasket materials that provide a water-resistant seal between the cover and the truck bed, which over time results in wear and tear to the paint finish of the pickup truck bed rails. These effects reduce the resale value of the pickup truck vehicle. The inside surface of the FRP cover is usually unfinished and exposes the hand-rolled FRP materials. Cover manufacturers add a secondary painted surface finish or apply a non-woven fabric to hide the rough inside FRP surfaces at extra cost in order to over-come this appearance problem. Finally, in order to adapt the crowned application surface of the FRP cover to the flat rail surfaces of the truck bed, the FRP cover manufacturers use added inserts. This arrangement is typically ineffective because the additional inserts do not adequately compensate for the front-to-back crown along the sidewalls or the side-to-side crowns about the rear and front walls of the FRP cover. Water penetration occurs when a proper seal is not achieved, and water can damage cargo stored in the truck bed.
An advanced thermoformed cover substantially overcomes these problems. A thermoformed cover is approximately 35% lighter than an equivalent sized FRP cover, and is easier to remove and re-install at the convenience of the vehicle operator. A lighter weight thermoformed cover decreases long-term fuel consumption and therefore the cost of operating the vehicle. Elements of the second inside sheet of a thermoformed cover can be adapted to conform to the horizontal plane defined by the truck bed rails upon which the cover rests. Therefore, while the first sheet can be crowned to present an attractive appearance and overcome the FRP cover problem of xe2x80x9cdishingxe2x80x9d, the second sheet can be adapted to provide a uniform compression seal about the truck bed rails which minimizes damage to the painted surfaces. A lighter weight thermoformed cover also produces less deflective forces about the prop mounting points and hinge mechanisms, which in turn reduces the incidence of sheet metal deformation and warping. The inside molded appearance of the thermoformed cover is superior to the rough inside surface appearance of the FRP cover.
Another consideration is that roughly 90% of all FRP covers are custom painted to match the color scheme of the pickup truck vehicle. A problem with painted FRP covers is that painting grade gel coat resins have low impact strength, and where the FRP cover edges are exposed and impacted, the painted gel coat chips off the application of FRP paint systems usually includes the use of sensitive activators, agents and solvents that cause worker safety and environmental problems.
Another consideration is that FRP covers are difficult to align and install because they are typically poorly executed in design and difficult to handle because of their heavy weight. For example, FRP covers occupy a position above the truck bed rails. The FRP cover includes a foam gasket about its outside margin coexistent with the top of the truck bed rails. This gasket is meant to compress against the rail of the truck bed to prevent water penetration. FRP covers are crowned to reduce the appearance problem of xe2x80x9cdishingxe2x80x9d at the center. The crown along the front bed wall increases to the middle. If an insert that compensates for this crown in not interposed between the FRP cover crown and the top of the front bed rail, the cover will only restrict water penetration. The FRP cover manufacturers will use an additional combination of strips of the insert material used to reinforce the crown, but this is ineffective because the strips are uniform in thickness and are not crowned themselves. The second sheet of the thermoformed cover can be molded to provide a consistent distance between the inside surfaces of the cover and the outside painted surfaces of the truck bed rails. This arrangement allows the compression points of the thermoformed cover to be evenly distributed and aligned for installation, rather than focused at the crown low points and mal-aligned to the four corners in the case of FRP covers.
Another consideration is that when an FRP cover is installed, the FRP cover is usually lifted up by one person standing on the tailgate, and is attached to front wall and the sidewalls by a second or third person. The crown of the FRP cover does not catch on the front wall to prevent the heavy cover from shifting forward against the passenger cabin upon lifting. When the hardware is affixed at a bind, the cover warps or the sheet metal deforms. Elements of the FRP cover do not characteristically protrude below the horizontal plane defined by the top surfaces of the truck bed rails.
A characteristic of FRP covers is that the pneumatic props are mounted to the side rail and the cover. This arrangement produces a constant opening force upon the cover when the cover is closed, and in case of heavy-duty FRP covers produces significant focussed prop pressure points. These can deform the sheet metal structures of the truck bed rail when the cover is closed under stress as well as deflect the FRP crown over time.
Another consideration is that cover consumers no longer accept vehicle damage, because pickup truck vehicles are becoming increasingly expensive to purchase and operate. FRP cover manufacturers have begun to use fabricated aluminum frames to retain the cover in a position above the truck bed rails. The aluminum rails offer a no-drill installation as well as means for deflecting hinging, prop and cover weight stress upon the painted metal surfaces of the pickup truck vehicle. U.S. Pat. No. 5,688,017 to Bennett is representative of the frame systems used by FRP cover manufacturers. The added economic cost, increased weight and installation difficulties associated with hard cover frame systems is the FRP cover industry""s attempt to correct the damaging effects of FRP cover use
Another problem is that there are an increasingly large number of pickup truck types and body styles. An FRP manufacturer must develop a unique lay-up mold in order to produce a cover model for each truck bed size and body style. The consequences of this requirement are varied. When coupled with the paint factor noted above, it can take up to two weeks before a color matched cover can be delivered and installed on the pickup truck for the vehicle owner. The inventory cost to maintain a virtually unlimited selection of color-matched covers in a wide range of truck bed types and body styles is prohibitive. Therefore the cover consumer must be prepared to wait for the manufacturer to produce, paint and deliver an FRP cover to the dealer before the product can be installed onto the vehicle. The FRP cover purchasing process is time-consuming and is not suitable for fulfilling a consumer""s need for immediate gratification. This consequence, plus the high cost of an FRP cover, are the principle factors which have contributed to the increasing popularity of standard black soft covers among pickup truck owners. Accordingly, a need exists for a small number of hard covers that can be adapted to fit a wide variety of truck bed types in the conventional body style sizes. These body style sizes include full-size long and short beds, compact-size long and short beds, intermediate-size long and short beds and full and compact-size sport and flare-side beds. A hard cover of this description would reduce the inventory requirements within the distribution system, and compress the lead-time for delivery. This type of hard cover would also provide a more robust and tamper proof product than a soft cover which can be slashed open with a knife by vandals and thieves.
Another problem with conventional FRP covers is that they use opposed pneumatic props to support the cover in an open position. The disadvantage of this arrangement is that access to the cargo area of the pickup truck bed is restricted from the sides by the props.
It is a primary objective of the present invention to provide a rigid cover for a pickup truck bed in order to protect cargo and property against weather and from vandalism.
Another objective is to provide a cover comprised of two sheets of thermoformed plastic, which offers several economic advantages. Thermoforming offers clear production volume advantages, which will permit the more advanced product to be distributed into a wider market territory. Thermoforming is lower cost and will allow the consumer to benefit through lower pricing. Thermoforming poses less risk to worker safety because the process does not release harmful emissions and violates. Thermoforming materials are sensitive to the environment and are 100% recyclable.
Another objective is provide a cover that offers several consumer friendly benefits. A lighter weight thermoformed cover is more user friendly allowing the vehicle operator to install and remove the cover with greater ease. A lighter weight cover consumes less fuel to reduce vehicle-operating costs over time.
Another objective is to use a processing technology and materials that are safer for the environment and have less worker safety issues.
Another objective is to produce a cover with a full perimeter watertight seal to prevent cargo damage and paint abrasion.
Another objective is to encapsulate the cover hardware between the two sheets of the cover to provide a more attractive appearance and finish.
Another objective is to add front retaining wall to the inside sheet of molded plastic to aid in the installation and removal of the cover from the truck bed. A feature that can be added includes an alignment guide for installation.
Another objective orientates the cover lifting springs to produce a constant closing force, which reduces deflection of the cover and compensates for elevated temperature conditions that may cause the cover to deflect.
Another objective adapts the cover to use coil springs operable from the front of the cover in substitution of opposed pneumatic props that restrict access to the truck bed from the sides. The objective provides springs, which do not interfere with the installation of other truck bed accessories.
Another objective adds load bearing and shape retaining strength to the second inside sheet of thermoformed plastic with the addition of molded in reinforcing elements. The individual reinforcing elements may themselves include stress reducing features comprising notches and interconnecting bridges, and are preferably arranged in patterns that impart additional front-to-back and side-to-side cover crown strength while deflecting localized hinging and focussed pressure stress points.
Another objective increases strength to the cover where the cover""s crowned top surface transitions into the down-turned cover walls that define a perimeter lip. A hollow area along the linearly extending transition is provided between the two sheets forming the cover to increase load-bearing strength.
Another objective inserts load-bearing and cover shape retaining members between the two sheets comprising the cover, which members enable the cover to be constructed in thinner gauge sheets that improve strength-to-weight and cost/price ratios.
It is still yet another set of objectives to produce a cover that is adaptable to a wide range of truck beds within certain truck bed size categories.
Additional objectives therefore include providing a cover assembly product line comprising a small number of covers in common sizes, and a large number of rail adapter kits that are specific to each make and model of truck bed in the common sizes. The cover component of the assembly incorporates the cover features listed above in connection with the improvements over conventional FRP style thermoformed covers. The rail components themselves include other features.
Another objective is provide a four part rail kit, comprising one front wall and two side wall components operable to engage the truck bed rail and a rear wall component operable to engage the rear wall of the cover component. This arrangement produces a full perimeter boarder appearance and operates to restrict the tailgate from being opened without first opening the cover. The tailgate is maintained in the dosed position under lock and key by the cover to prevent theft and vandalism. In alternate arrangements, the rear wall component of the rail kit is operable for mounting upon the tailgate, but this arrangement is not always preferred because tailgates are not amenable for clamps or no-drill installation.
Another objective is provide front and side wall rail components with a channel to receive the down-turned walls of the common sized cover. The position of the channels on the truck bed adapting rail components is pre-determined by the relative position of the perimeter margin of the cover component. The channel includes draining features and may be reinforced to add strength to rail components and prevent paint abrasion of the truck bed.
The rails include details that are further operable to enclose clamps that attach the rail components to the truck bed rails for appearance purposes and a no-drill installation. The front rail channel includes an angled portion designed to receive the pivoting front wall of the cover. The rail components may be constructed out of a single sheet or a plurality of sheets molded and bonded together for hardware supporting and cover bearing strength.
Briefly, in accordance with this invention, there is provided a twin-sheet cover for installation onto the bed rails of a pickup truck. The cover, including hardware may be operable with the truck bed alone, or in cooperation with rail adapting kits.
Other objects and advantages of the present embodiments will become apparent from the following descriptions and appended claims when taken in conjunction with the accompanying drawings.